WFM electronics Alexandra Andersson WFM experiment in CLEX

WFM electronics Alexandra Andersson

WFM experiment in CLEX § Wakefield Monitors implemented in two accelerating structures TD 24 (tank version, without Si. C loads (except for the WFM)) § Each WFM will study two different modes: TM like mode at ~ 18 GHz (+ hybrid recombination) TE like mode at ~ 24 GHz § RF Design finished (Gdfid. L + HFSS simulations) § Mechanical design under progress (CERN) § Connectors, Vacuum cables, 3 d. B/180° Hybrids ordered Port signals for beam offset ∆x=1 mm Waveguide bend TM (+ perfect hybrid) Si. C load 18 GHz TM modes TE modes F. Peauger – CTF 3 committee – 11/02/10 TE 24 GHz 2

Fabrication of the accelerating structures § Qualification of three firms for precise machining (2 prototypes) § Results of Firm n° 1: • Very low roughness of turned surfaces Ra = 0. 009 to 0. 022 (spec=0. 025) • Roughness of milled faces higher (factor of 10) but can be improved with monocristal cutting tool • Tolerances within 3 µm (spec=2. 5) • Planarity of 1. 7 – 3. 2 µm (spec=2µm), can be improved by better stress relieve process Very promising results § Results from Firms n° 2 and 3 expected in few weeks § Schedule (target): - all the disks for the two structures machined: - structures ready for test with beam on TBTS: But challenging planning mid 2010 end 2010 ? § Note: need maybe an additional BPM on TBTS, just before the structure (to be discussed) F. Peauger – CTF 3 committee – 11/02/10 3

Detection scheme • • • Waveguide to coax Power limiter Low Noise Amplifier Down mix with 18 GHz (24 ->6, 22. 5 ->4. 5, . . . ) Power splitter Magnitude detected with logarithmic diode detector Band. Pass around 6 GHz for phase detection Compare to phase of the 12 GHz RF. Use Local Oscillator of common derivation

Detection Scheme

LO generation

Noise Loss/Gain Noise, F Gain casc. Noise Casc. Gain casc. Component [d. B] Noise Figure Gain linear (linear) d. B/Hz d. B damped waveguide -10. 0 0. 1 10. 0 -10. 0 vacuum cable -2. 0 0. 6 1. 6 0. 1 15. 8 12. 0 -12. 0 vacuum feedthrough -0. 5 0. 9 1. 1 0. 1 17. 8 12. 5 -12. 5 Waveguide -> sma transition Waveguide and flanges Waveguide -> sma transition PIN diode limiter Low Noise Amplifier Mixer Power Splitter 0. 0 1. 0 0. 1 17. 9 12. 5 -3. 7 0. 4 2. 3 0. 0 42. 0 16. 2 -16. 2 0. 0 -2. 5 -18. 8 30. 0 -7. 0 -5. 0 0. 0 2. 5 1. 0 0. 6 1. 0 1. 8 0. 0 42. 4 75. 4 16. 3 18. 8 -16. 3 -18. 8 2. 5 7. 0 5. 0 1000. 0 0. 2 0. 3 1. 8 5. 0 3. 2 13. 3 2. 6 0. 8 134. 0 134. 3 135. 2 21. 3 11. 2 4. 2 -0. 8 d. Bm/Hz (-174 d. Bm/Hz + Casc. Noise Figure) m. W/Hz m. W d. Bm -152. 7 5. 4 E-16 1. 1 E-06 W -59. 7 1. 1 E-09

Frequencies and phases Frequency Phase LO 1 (crystal oscillator) 16. 384 MHz φ1 LO 2 (crystal oscillator) 48 MHz φ2 LO 3 (crystal oscillator) 75 MHz φ3 Mixer 1, LO 1 x. LO 2 64. 384 MHz φ1+φ2 Mixer 2, LO 2 x. LO 3 123 MHz φ2+φ3 Mixer 3, Mix 1 x. Mix 2 187. 384 MHz φ1+2φ2+φ3 LO = Mix 3 x 16 (divide-by-N PLLL) 2998. 144 MHz φLO=16(φ1+2φ2+φ3) 2 x. LO (frequency doubler) 5996. 288 MHz 2φLO 6 x. LO (frequency tripler, doubler) 17988. 864 MHz 6φLO WFM signal 23988. 4 MHz φWFM Down. Mix 1 = WFM x (6 x. LO) 5999. 536 MHz φWFM -6φLO IQ 1=Down. Mix 1 x(2 x. LO) 3. 248 MHz φWFM -8φLO RF signal 11994. 2 MHz φRF Down. Mix 2 = RF x (2 x. LO) 5997. 912 MHz φRF -2φLO IQ 2=Down. Mix 2 x(2 x. LO) 1. 624 MHz φRF -4φLO Phase WFM-RF = IQ 1 -2 IQ 2 φWFM -2φRF

Waveguide

194 mm Waveguide 534 mm

Waveguide